Is there a piece of software that tells you which domains the traffic is coming from for a particular domain?
You can use Google Analytics, that will break down all of your traffic and tell you exactly where it is coming from. It will be able to tell you which domains have sent you traffic on a daily basis. Best part is the service is also free.
Very true, google analytics even kicks butt compare to awstats or webalizer which many people for some strange reason swear by. Awstats and webalizer get to much invalid data, analytics will just track the stats you want, plus many other useful reports. Good call SEMSpot.